Iranians walk past a huge anti-US billboard reading in Persian, 'The devil army will be drowned in the Persian Gulf', erected on Enghelab Square in Tehran on September 23, 2026. Ever tighter US sanctions intended to cripple Iranian aviation come into force on September 23, after Washington vowed to "shut down" Tehran's carriers and punish anyone doing business with them. In their first acknowledgement of disruption, Iranian media reported late Tuesday that flights to the Iraqi and Omani capitals would be cancelled the following day, but other routes would be unaffected. (Photo by AFP via Getty Images) /